feat(tvix/eval): nonrecursive deep_force() r/7175

This commit implements deep_force() nonrecursively, by maintaining
an explicit stack rather than using the call stack for recursion.

As an added bonus, we don't need to pass around the SharedThunkSet
anymore, and can in fact completely eliminate SharedThunkSet.

Change-Id: I7c4f59f37834d451a28bf6be317eb0a90eac4ee6
Reviewed-on: https://cl.tvl.fyi/c/depot/+/10252
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>
Autosubmit: Adam Joseph <adam@westernsemico.com>

1 files changed, 0 insertions, 11 deletions

diff --git a/tvix/eval/src/value/thunk.rs b/tvix/eval/src/value/thunk.rs
index cafa8275de..a67537f945 100644
--- a/tvix/eval/src/value/thunk.rs
+++ b/tvix/eval/src/value/thunk.rs
@@ -432,14 +432,3 @@ impl ThunkSet {
         self.0.insert(ptr)
     }
 }
-
-#[derive(Default, Clone)]
-pub struct SharedThunkSet(Rc<RefCell<ThunkSet>>);
-
-impl SharedThunkSet {
-    /// Check whether the given thunk has already been seen. Will mark the thunk
-    /// as seen otherwise.
-    pub fn insert(&self, thunk: &Thunk) -> bool {
-        self.0.borrow_mut().insert(thunk)
-    }
-}